Thread: what is time, really?

I've been trying to come up with some comprehensive way of defining time as an entity. Even if taken with space in the fabric of space-time through general relativity, there is still a component, time, that is independently variable, with respect to a then dependent variable space, and vice versa. In light of this, I am really curious as to what, exactly, time is. Is it some dimension of existence? Is it a constant that flows through our plane of reality? Is it something that can be altered? Or is it a simple construct of man? I would love to have some kind of talk with people in (ideally) much higher degrees of education than myself, being fresh out of high school.

Time does not exist. It is only a concept/measurement developed by humans.

Disregarding Waveman's unsupported rants, the truth is that no one really knows all the answers when it comes to time. You should probably wait for someone more knowledgeable than me to answer, but as far as I know, what we do know is that time is an integral part of space-time and is changeable (specifically, motion and time are interrelated). The problem is that all the different theories treat time differently.

I consider it to be a a priori facet of the pure intellect. It is real, just as gravity is real.

Time is basically a measure of relative movement. No movement can exist in a non-relative way and neither can time. So, they are inseparably linked to each other. When you have movement (through space), you have time. Space-time.

Originally Posted by Waveman28

Time does not exist. It is only a concept/measurement developed by humans.

The Philosophy forum is the third one down in Social Sciences.

I've been trying to come up with some comprehensive way of defining time as an entity. Even if taken with space in the fabric of space-time through general relativity, there is still a component, time, that is independently variable, with respect to a then dependent variable space, and vice versa. In light of this, I am really curious as to what, exactly, time is.

In this instance, I must say that this is an impossible question to answer. For one thing, it's coexistence with speed leads to circular definitions. For general relativity, time was defined by the time it took till light struck you i.e. if a photon took a longer time than usual to reach you, this is directly equivalent with time slowing down, and vice-versa.

Time, as can be seen from the above definition, can slow down or speed up, conforming to Waveman's notion of a system of measurement. However, time can always be thought of as a dimension; this can be seen if you take the 4-manifold world of general relativity.

Time itself can lead to certain paradoxes as well; Zeno's fourth and second paradox are examples of these. However, that leads down the road to philosophy, so let's forget that for now.

It is, however, fundamentally impossible to define time, just as impossible it is to define what 0/0 is really equal to.

Might I suggest you try to treat time as, in the language of physicists, a fundamental entitiy i.e. it does not require the existence of other things to be defined. An ideal definition of time should be independent of the notions of speed, distance and other such notions.

so, saying that the time it takes for one photon to travel some distance is one unit of time, time can be altered if, say, we were to place a gigantic point of gravity somewhere near the trip of photon, and, in effect, slow or speed the rate that the photon travels; all assuming that the origin of the photon and your position are fixed and unmoving. Personally, I don't quite understand how time can be sped up or slowed down, the individual would experience changes internally that would be unaffected by whatever affects the proton's movement, and each of those processes are dependent on time as a dimension. for instance, even if the rate of the proton is slowed to 1/2 of its usual, unaltered, rate; the subject receiving the proton will undergo all the same processes, for the sake of argument lets say the subject is a pendulum, as if the proton were not affected, and the pendulum will make twice as many passes in the same amount of time, as defined in the first sentence, and yet the rate of movement of the pendulum, locally, would have never changed at all. I may have missed the point, but the idea is sketchy to me that time, as it is, can be altered in any way, except for the conditions of moving really really fast and moving really really slow, and still that's an alteration of time dependent upon motion, and it seems to me that that would correlate time as a dependent function of motion. Please correct me if I'm wrong, and again, I haven't a real education on advanced ideas in physics.

The concept of time is a human idea, I don't think it's currently possible for us to acurately measure something on a universal scale as acurate as time appears to be measured



Time is essentially non existant, it's a measurement of the decay of the universe, Entropy is a measure of disorder and universal balance, and this is essentially what time measures, it measures the quantum decay of everything and the energy dissapation throughout the universe,
By this measure we can do things like assume the begining and ending of time, when all energy is equally distributed throughout the universe to such an extent it won't move again (The Big Freeze Theory) time will technically end, and in reverse time began at the instance when all energy was in one point indefiniately (a Singularity?)


So Time Travel would simply be the reverse of entropy, reversing the decay of the universe, currently impossible but theoretically possible on a practical level without ideas of wormholes or space-time continiums

Originally Posted by Booms

Time is essentially non existant, it's a measurement of the decay of the universe, Entropy is a measure of disorder and universal balance, and this is essentially what time measures, it measures the quantum decay of everything and the energy dissapation throughout the universe,
By this measure we can do things like assume the begining and ending of time, when all energy is equally distributed throughout the universe to such an extent it won't move again (The Big Freeze Theory) time will technically end, and in reverse time began at the instance when all energy was in one point indefiniately (a Singularity?)


So Time Travel would simply be the reverse of entropy, reversing the decay of the universe, currently impossible but theoretically possible on a practical level without ideas of wormholes or space-time continiums

No. You can't link entropy and time together to create a neat Yin/Yang. Entropy is unrelated, a measure of randomness. Time is not a measure of decay.

Originally Posted by MagiMaster

Disregarding Waveman's unsupported rants, the truth is that no one really knows all the answers when it comes to time. You should probably wait for someone more knowledgeable than me to answer, but as far as I know, what we do know is that time is an integral part of space-time and is changeable (specifically, motion and time are interrelated). The problem is that all the different theories treat time differently.

I will prove it to you then. Why do we always perceive time as being the same, no matter how fast we are moving? Because it doesnt "exist"! Someone else will see our CLOCKS slowing down, but that does not mean TIME is slowing down. As we move faster, the FREQUENCY of our clock becomes slower, not time, simply because time is just a perception generated by our minds.

If you think that constitutes proof, try again. Even without the faulty logic, that would be a pretty flimsy argument. With the errors it is basically meaningless.

The clocks are not what's changing. Any periodic event will be observed as remaining constant if you are moving with it, but changing otherwise, no matter what the periodic event is. What is your explanation for this? (You can't say it doesn't exist, because it's been measured. Those measurements are valid no matter why they happen.)

Originally Posted by MagiMaster

If you think that constitutes proof, try again. Even without the faulty logic, that would be a pretty flimsy argument. With the errors it is basically meaningless.

The clocks are not what's changing. Any periodic event will be observed as remaining constant if you are moving with it, but changing otherwise, no matter what the periodic event is. What is your explanation for this? (You can't say it doesn't exist, because it's been measured. Those measurements are valid no matter why they happen.)

Is this for real? Lets review how we define time. When we do something such as swing on a swingset, we can compare that with another event such as how many times a clock has ticked. We may have swung 5 times, whilst the clock may have ticked 20 times. All we are doing is comparing 2 different frequencies, its just a relative difference and it goes no further than that.

If two people are both travelling at the same time, obviously they will not notice any difference in frequencies between there clocks frequencies are both slowed at the same rate. This is quite basic.

okay, this is funny, you are speaking relativistically. My motion, relative to your motion, causes my perception of events to, possibly, be different than your perception of events. This, by no means, defines time as nonexistent, only dependent upon motion. But, also, consider a clock that uses a photon, perpetually bouncing between 2 mirror plates, at rest state. You can define time by the rate at which the photon in the box bounces, one cycle being one unit. Governed by the speed of light, being that the photon will always, ALWAYS, be traveling at the speed of light. You send the box moving, and what happens? the horizontal motion, the speed, will alter the vertical, time, as governed by the hypotenuse of a triangle created by the two legs, speed and time, being c, the speed of light. I'm sorry, but that is a horrible way to prove the non-existence of time, you are merely treating time as a constant altering a variable of motion[/i]

Originally Posted by Arcane_Mathamatition

okay, this is funny, you are speaking relativistically. My motion, relative to your motion, causes my perception of events to, possibly, be different than your perception of events. This, by no means, defines time as nonexistent, only dependent upon motion. But, also, consider a clock that uses a photon, perpetually bouncing between 2 mirror plates, at rest state. You can define time by the rate at which the photon in the box bounces, one cycle being one unit. Governed by the speed of light, being that the photon will always, ALWAYS, be traveling at the speed of light. You send the box moving, and what happens? the horizontal motion, the speed, will alter the vertical, time, as governed by the hypotenuse of a triangle created by the two legs, speed and time, being c, the speed of light. I'm sorry, but that is a horrible way to prove the non-existence of time, you are merely treating time as a constant altering a variable of motion[/i]

You definately cannot define time as being the rate at which the photon in the box bounces. That is the FREQUENCY. People often confuse frequency with what they believe is time. Time cannot be measured, number one because it does not really exist and two, measured events are only relative to others. This is why general relativity's explainations are incorrect and lorentz's relativity is corerct. Both lead to the same predictions and conclusions, but Lorentz gives a much better and logical reason for the effects of relativity.

Originally Posted by Kukhri

No. You can't link entropy and time together to create a neat Yin/Yang. Entropy is unrelated, a measure of randomness. Time is not a measure of decay.

I'm not making neat yin/yang, Time and entropy are measures of similar things, and entropy is only an unrelated measurement of randomness on a small scale, it measures the disorder of things, water is less organised that lead and therefore has higher entropy, on a universal scale entropy measures the order of things, the higher entropy something has the closer it is to being evenly distributed throughout the universe


as thing's decay they increase in entropy, a rotten hedgehog is going to have higher entropy than a living one because it's more disorganised than a functioning creature, the more rotten it get's the higher entropy it will have, it will also have been rotting for a greater length of time, therefore time is a measure of entropy

as thing's decay they increase in entropy, a rotten hedgehog is going to have higher entropy than a living one because it's more disorganised than a functioning creature, the more rotten it get's the higher entropy it will have, it will also have been rotting for a greater length of time, therefore time is a measure of entropy

Yet one could claim that locally entropy is not increasing. New organisms are born every day and go in the opposite direction during growth. Despite this, time is running along fine and not slower or faster than the sun for instance. What I am saying is that just because overall entropy increase provides an arrow, does not mean that this arrow is time. Where we do see time is in relative movement.

The clock on your wall is moving at a certain speed relative to something you are measuring and define the thing you are measuring according to it. This is true whether we are there to see it or not in the form of relativity. This measurement is independent of the entropy of two events being compared to each other.

Originally Posted by Waveman28

You definately cannot define time as being the rate at which the photon in the box bounces. That is the FREQUENCY. People often confuse frequency with what they believe is time. Time cannot be measured, number one because it does not really exist and two, measured events are only relative to others. This is why general relativity's explainations are incorrect and lorentz's relativity is corerct. Both lead to the same predictions and conclusions, but Lorentz gives a much better and logical reason for the effects of relativity.

Would you care to define frequency without referring to time? Otherwise, you're contradicting yourself by saying that frequency isn't time without actually being able to separate the two.

In fact, frequency really is the only measure of time period. A wall clock either counts the frequency of a pendulum, a spring or a quartz crystal. An atomic clock counts the frequency of a few atoms. Frequency is, in some sense, time. Yes, frequency is relative. Yes, time is relative.

Originally Posted by MagiMaster

Originally Posted by Waveman28

You definately cannot define time as being the rate at which the photon in the box bounces. That is the FREQUENCY. People often confuse frequency with what they believe is time. Time cannot be measured, number one because it does not really exist and two, measured events are only relative to others. This is why general relativity's explainations are incorrect and lorentz's relativity is corerct. Both lead to the same predictions and conclusions, but Lorentz gives a much better and logical reason for the effects of relativity.

Would you care to define frequency without referring to time? Otherwise, you're contradicting yourself by saying that frequency isn't time without actually being able to separate the two.

In fact, frequency really is the only measure of time period. A wall clock either counts the frequency of a pendulum, a spring or a quartz crystal. An atomic clock counts the frequency of a few atoms. Frequency is, in some sense, time. Yes, frequency is relative. Yes, time is relative.

At present, 1 second is defined as 9,192,631,770 complete oscillations of a caesium-133 atom. That is not time itself, it is a value which is compared to another event. For example one person can now say, "I have traveled 40 meters while the caesium 133 atom has completed 9,192,631,770 oscillations. "Time" doesnt come into it, we just generated a ratio by comparing two different states.

I fail to see your point though. My point is that a moving cesium atom (and any other atom, and any other event) will seem to oscillate slower or faster than one that isn't moving relative to you. Therefore, a second will seem to take more or less than your second for someone moving relative to you.

Further experiments have shown that this does indeed happen in a real, physical way. Relativity is a possible explanation for why this might happen. Relativity also makes further predictions that have been born out in yet more experiments.

Anyway, you're free to argue about the why's, but not about the what's. Those are established by many repeated measurements of the results of experiments. Just be sure your why's match the experiments because the what's will continue to exist no matter why we think they should or shouldn't.

how, then, do you measure the speed? since there is no time, how does one go about measuring change? relative rates can only take you so far, to define the speed, or the velocity of an object, you must have some unit to compare the rate of change to, regardless of whether its anything like cesium, a clock spring, or a bouncing photon, its still some unit of change in distance with respect to some unit of time. you can't avoid the aspect of time inherent in all of these examples of yours. A frequency is defined as the rate at which some cyclical change completes one full cycle. we use that rate as a standard of time to be applied to another event and thus, we have a unit of time. time can be defined by the rate of cyclical movement with respect to some other motion. please correct me if I'm wrong.

No, you see time is only a perception. We percieve it as being the same regardless of the situation. For instance we will get bored just as easily travelling near the speed of light as we will if we are "stationary". Frequencies however, do change, which is what we use to indirectly measure time. This does not mean our "perception" of time will change, just how it is recorded. This is the strongest evidence that time itself has no existance.

How can all clocks (that is, all periodic events) change without changing a human's internal clocks (the periodic firing of certain groups of neurons, as well as the chemical systems in the cells, etc.)? Do you have any evidence to support this?

Originally Posted by Arcane_Mathamatition

I've been trying to come up with some comprehensive way of defining time as an entity. Even if taken with space in the fabric of space-time through general relativity, there is still a component, time, that is independently variable, with respect to a then dependent variable space, and vice versa. In light of this, I am really curious as to what, exactly, time is. Is it some dimension of existence? Is it a constant that flows through our plane of reality? Is it something that can be altered? Or is it a simple construct of man? I would love to have some kind of talk with people in (ideally) much higher degrees of education than myself, being fresh out of high school.

Well, let me answer this for you. It's a congruity between two differential viewpoints, which seem contradictory or maybe even complimentarity, the last being a relationship due to complimentary systems, like speed and position.

If you want to define time as an entity, then you could just simply use a bit of philosophy - indeed, the philosophy would be, ''if time was a real thing, how can we ever take it physically?''

The answer is hopefully obvious, it means that time is seen as an arrow, a psychological arrow really, where an observer has some distinction of a past and a future, cause by a very low entropy at some infinitesimal time t<1, or the beginning of everything.

It seems now that time is simply nothing but how we interpret our perception of some type of event passing, rather than niavely thinking that time would still pass if an observer was not present. Some scientists have even concluded that time in all it's array maybe itself an observer-dependant theory, which would make the mind somehow time itself.

Other than that, time is nothing but a mathematical measuring stick, that doesn't even evolve from a cosmological viewpoint, such as the De-Witt and Wheeler equation.

Originally Posted by MagiMaster

How can all clocks (that is, all periodic events) change without changing a human's internal clocks (the periodic firing of certain groups of neurons, as well as the chemical systems in the cells, etc.)? Do you have any evidence to support this?

Of course. Lets say I speed up to near the speed of light, i think my clocks are perfect and that external observers are the ones whos clocks frequencies are slowing down. However, they think the same. So we can conclude from this that "time", so to speak, does not exist, frequencies change, but "perception of time" does not (because its not real).

how do you prove that something doesn't exist?

Hello, Im not about to say Im some physics genius but Ill try to explain it the best I can.

To me time is not so much a plane, but a variable that coincides with location. You understand the idea of location as width, height, and length, or XYZ. So you put a location form a reference point using XYZ. But a moving object is not always at the same point so its coordinates are always changing as time changes.

Lets pretend there is an object that is moving in a circle around us, we become the refernce point. At 12:00 its location is 2,3,4 so we can write it as (XYZT, or 2,3,4,12:00) but one hour later its location is 3,-4,5. That is then written as 3,-4,5, 1:00.

Time isn't some plane of reality that can be described, but at some time everything is somewhere and thats what the 4th dimension (time describes). the time relative to the location.


Im sure some will say this is wrong, but this how Ive seen it and its worked for me)

O and by the way, time both does and does not exist. Before humanity invented it, it did not exist, but now that we have it does. It's the same as the computer that we all are typing on, before it was invtented it did not exist, but now it does. Time is just something that cannot be seen unless you think about. How could something that does not exist cause us to wake, cause us to move and cause us to move. Time is as real as you or I. But it is something that only humans can use and control. And also without time, we could not have history because everything would be happening all at one point, all right now, because there is no past or future without time.

Originally Posted by Arcane_Mathamatition

how do you prove that something doesn't exist?

Usually by demonstrating that its existence would lead to an absurdity, the technique know as reductio ad absurdum.

That is the technique used to prove, for instance, that there is no largest real number. Suppose that there were a largest real number, call it X. Then X +1 is also a real number and X+1>X. But that contradicts the definition of X as the largest real number.

Sorry for resurrecting this thread, but I need to make sure I've got this right.

A generalized definition of time is: a measurement of physical change relative to the speed of light. Is this how time is defined in physics?

My previous view was that time was simply a measurement of change. But apparently that's too vague.

Ugh... I probably got it all wrong...

Originally Posted by Obviously

Sorry for resurrecting this thread, but I need to make sure I've got this right.

A generalized definition of time is: a measurement of physical change relative to the speed of light. Is this how time is defined in physics?

My previous view was that time was simply a measurement of change. But apparently that's too vague.

Ugh... I probably got it all wrong...

About as close as you are going to tind to a definition of time is "Time is what clocks measure". That may not be very satisfying, but that it really about the only definition that you are going to find. "Absolute time" died a hard death with the introductin of the theories of relativity.

time is a measurmen of now and then and what will be now and then but if we are taking about actual time it is nothing but nothing bu what would thier be with no time thier would be nothing so it is realy a 4th dimension that bringgs life to life

Over all a big waste of time, maybe we should ponder more useful concepts.

and who is to decide what is useful, you? no-one can decide what is 'useful' as many discoveries have been made by people going against popular opinion and looking into those 'waste of time' things. Albert Einstein thought Quantum mechanics was a 'waste of time'!

Originally Posted by Arcane_Mathematician

I've been trying to come up with some comprehensive way of defining time as an entity. Even if taken with space in the fabric of space-time through general relativity, there is still a component, time, that is independently variable, with respect to a then dependent variable space, and vice versa. In light of this, I am really curious as to what, exactly, time is. Is it some dimension of existence? Is it a constant that flows through our plane of reality? Is it something that can be altered? Or is it a simple construct of man? I would love to have some kind of talk with people in (ideally) much higher degrees of education than myself, being fresh out of high school.

There are two aspect to this question of time and we see quite clearly in physics because there is both a symmetry with respect to time and an asymmetry with respect to time (called the arrow of time).

Time is a dimension or degree of freedom in the mathematical structure of the universe, which according to string theory is one of eleven such dimensions. In this we see the symmetrical aspect of time, for the mathematical equations of physics are quite symmetrical with respect to time, making no distinction between past and future.

This presents a puzzle because we do not experience time in a symmetrical manner. We would be at quite a loss except that there are elements of physics which do distinguish between past and future. The first is entropy in thermodynamics and the other is decoherence in quantum physics. Whether you go be the copenhagen interpretation and its wave collapse or by Everett's many world interpretation, past and future are clearly distinguished. In the copenhagen interpretation superposition collapse and thus the superposition of possibilites in the future become a single actuality in the past. In the many worlds interpretation we find the same thing simply expressed in a different way as the reality diverges into a greater multiplicity in the direction of the future rather than the past.

I think this also explains quite clearly why we do not experience time in a symmetrical manner. First, the asymmetry with respect to entropy is directly connected with the phenomenon of life because life only exists in the far from equillibrium environment where there is a great increase in entropy going on all the time. Second, we experience the future as a divergence of possibilities all the time and I believe that this is in fact what human consciousness is all about.

I think one has to ask if all forms of intelligence were removed from the known universe would time exist, or just changes in matter and energy? Without intelligence to quantify the differences between one change in matter or energy to another change in matter or energy time as we perceive it doesn't really exist. Change exists of course, but without intelligence to measure that change the true concept of time doesn't really exist. One can argue this of course because our intelligence doesn't allow us to think otherwise. We have absolutely no way to measure periodic change intervals without referencing these changes with other changes. Without us, change continues to happen it just is not measured.

Removing all concepts of time would not change the fact that matter and energy throughout the universe often change in a repeating pattern. Intelligence comes along and compares this repetition with other changes and we now have our concept of time.

From our point of view time does exist. The universe however doesn't require our definition of time to function as normal. I'm pretty sure this could be argued back and forth to death. I actually think both parties are correct. It exists and yet without intelligence it doesn't have meaning or actual purpose.

Time is so dependent on movement that I think some find it impossible to think of change without time. This is kind of a chicken and egg topic. I realize by typing all of this that it's next to impossible to have a truly correct answer as the finer details can be argued to death. You'll never change if you don't find the time to move. You'll never have the time to move if you don't start to change.

I think time is simply the flow of one point to the next. like if you have a lot of pictures of a car on a track, you put them together and the car is moving. Time is the passage from one picture to the next and how things change over a period.

So no movement equals no time?

it would appear so

Originally Posted by fizzlooney

So no movement equals no time?

Only if your talking about everything everywhere in known existence not moving. If one thing is not moving time still will pass if something somewhere else is. That something somewhere else gives us a frame of reference. If all existence were to stop moving even down to the sub atomic level then we could say time has stood still.

So the statement that time is a means of measuring change is an acceptable definition after all? One just has to remember there is no absolute position and that everything's relative, yes?

Originally Posted by mitchellmckain

[
I think this also explains quite clearly why we do not experience time in a symmetrical manner. First, the asymmetry with respect to entropy is directly connected with the phenomenon of life because life only exists in the far from equillibrium environment where there is a great increase in entropy going on all the time. Second, we experience the future as a divergence of possibilities all the time and I believe that this is in fact what human consciousness is all about.

Interesting speculation, but closer to religion than to physics.

Life may exist only where there is a far from static situation, but it certainly exists where there is effective thermodynamics equilibrium. Thermodynamics equilibrium is rather necessary for the defintion of entropy, an extensive and fundamentally statistical property of a system, to be meaningful.

The idea that the "arrow of time" is somehow tied to entropy is a widely known speculation. But there is no solid physics behind it, other than the purely empirical observation that entropy increases in the direction of positive time, which makes sense once one knows what time is. However, entropy is a statistical notion, and there is no notion in the underlying fundamental, non-statistical (to be distinguished from non-probabilistic) laws of physics that explains this fact. This relationship is one reason that Einstein expressed the opinion that time was probably fundamental in nature. But even Einstein could not define time in any rigorous way that did not involve some use of a "clock". So you are still left with the rather unsatisfactory "time is what clocks measure" definition.

Decoherence is also somewhat ad hoc as it requires looking at a quantum system as embedded in some environment and treating the original system in a non-unitary fashion.

In short, NOBODY has a good fundamental explanation as to what "time" is or why it behaves in the manner in which it does behave. There is reasonable speculation as to why time is apparently asymmetrical in the face of apparent symmetry in the governing equations, but there is still a deep mystery.

There is lots of speculation as to the source of human consciousness. Some of the more responsible has been done by Roger Penrose and is described in two books: The Emperor's New Mind and Shadows of the Mind. But this speculation is not amenable to experimental verification or refutation and is most definitely not physics. We don't even know WHAT consciousness is, let alone WHY it is.

Originally Posted by Obviously

So the statement that time is a means of measuring change is an acceptable definition after all? One just has to remember there is no absolute position and that everything's relative, yes?

I think the definition can get blurred. Time as a measurement and time as a concept. Time travel is a concept, etc. 60 seconds is a measurement. Time travel is only possible if one were to move everything back in to place exactly as it once was (even down to the sub atomic level), this however would still be in the future it would only appear to us to be the past. From our point of view it would appear very much real. I'm actually kind of shocked at the vast number of misconceptions about time. It's so simple yet people want to glorify it and make it something it's not. Can one have space time without time, sure but nothing would move, change, heat, radiate..etc.

I also love the concept of people traveling at the speed of light and not aging as much as those who are not , etc. What this is really saying is that the speed is having an impact on the matter and energy that make up the object (or person) in such a way as to slow it's sub atomic movement. It's like putting friction on the clock to slow it's internal workings. I know someone will go off on this one. Logically I don't see any other way to look at it. Slowing or speeding up matter internally will have an impact on our perception of time. All of existence could be speeding up and slowing down equally and we would have absolutely no way to detect it. All of our concepts of time are based on movement of matter or energy.

Originally Posted by (In)Sanity

I also love the concept of people traveling at the speed of light and not aging as much as those who are not , etc. What this is really saying is that the speed is having an impact on the matter and energy that make up the object (or person) in such a way as to slow it's sub atomic movement. It's like putting friction on the clock to slow it's internal workings. I know someone will go off on this one. Logically I don't see any other way to look at it. Slowing or speeding up matter internally will have an impact on our perception of time. All of existence could be speeding up and slowing down equally and we would have absolutely no way to detect it. All of our concepts of time are based on movement of matter or energy.

This is a rather dangerous way to look at the problem Traveling at speed DOES NOT affect the clock of the observer in motion. In fact the observer does not even know that he is in motion, and that is the whole point of an inertial reference frame. The interpretation that people traveling at high speed age less implies the existence of some absolute frame in which you can determine who is moving and who is not. There is no such absolute frame.

The "twin paradox" is an entirely different kettle of fish. It is only a "paradox" because of the invalid use of a non-inertial reference frame in formulating the "paradox".

General relativity is even more abstract. In GR there no such thing as a global reference frame, inertial or otherwise, and there is no such thing as "time" and no such thing as "space" in a global sense. Time and space are only realized once one picks a (local coordinate system), are figments of the particular coordinate system, and have no global meaning. In GR the question of what time is is subservient to the observation that it does not exist at all -- there are no global coordinates, spatial or time, for the full curved space-time manifold. The use of the words "time" and "space" in cosmological discussions involving GR also involve approximations of homogeneity and isotropy that are not correct in detail, and allow the development of a parameter that serves as a global time, but is not really time at all.

In special relativity the statement that someone is moving or that his clock has slowed down only makes sense in the context of some second observer. The entire theory of special relativity relates observations made by one observer to observations made by another observer, both in inertial reference frames.

Special relativity is really a theory about the very nature of space and time. It is not intuitive in the usual sense, and "logical ways of looking at it", which usually mean ways of interpreting special relativity in terms of our Newtonian intuition, are not really logical at all.

In short there is no "friction" no observer in an inertial reference frame notices anything at all out of the ordinary in his own reference frame. It is only the "other guy's" measurements that seem unusual by Newtonian standards.

In short there is no "friction" no observer in an inertial reference frame notices anything at all out of the ordinary in his own reference frame. It is only the "other guy's" measurements that seem unusual by Newtonian standards.

I didn't think otherwise. To me this makes perfect sense. Take for example if we were to freeze frame all matter and energy in a given area and instantaneously unfreeze it. The matter inside the area would of course have no awareness that this happened except for differences in what was remembered to be outside the area.

I think the key thing here is that there is no time without matter and energy. If we had an area of void space with absolutely nothing inside of it no time would pass relative to the inside of that area. If viewed from the outside we could determine how long that space existed in this state.

A ship traveling at the speed of light that takes one earth year to reach it's destination did in fact take one year to do so. If the clock on the ship starts to fall behind the clock on the wall at mission control back on earth this would have to indicate that the matter and energy used to make the clock work has in fact slowed in it's cycles. The occupants of course would have no awareness of this unless they had some kind of link back to an external reference point.

How did Einstein define time?

Maybe we could discuss that also.




(He clearly used "time" as a key factor in his theories and equations)

okay... I've skimmed over the first few posts and I want to add this:

If we stopped time, then that would imply that the photons stop moving, whick would imply pitch black. Does that mean that, if we were to stop time completely, of which my definition is nothing moves at all, we wouldn't be able to see anything? I'm presuming that you can still 'see' in the sense of being an observer who isn't stopped.

Originally Posted by asxz

okay... I've skimmed over the first few posts and I want to add this:

If we stopped time, then that would imply that the photons stop moving, whick would imply pitch black. Does that mean that, if we were to stop time completely, of which my definition is nothing moves at all, we wouldn't be able to see anything? I'm presuming that you can still 'see' in the sense of being an observer who isn't stopped.

oh, and another thing. If something is moving, it has energy, which means it has mass because mass is the most concentrated form of energy. Does that mean that if it isn't moving, then it wouldn't have energy, and wouldn't have mass? If we really stopped time to a standstill, then would we cease to exist?


Wow... that sounds creepy!

Originally Posted by theQuestIsNotOver

How did Einstein define time?

Maybe we could discuss that also.




(He clearly used "time" as a key factor in his theories and equations)

He didn't. He simply described how one could relate clocks in one reference frame to clocks in another (in special relativity). The implicit definition is that time is "what clocks measure".

In general relativity there is NO global definition of time. Einstein did not use time or space in formulating general relativity, but instead formulated the theory in terms of a 4-dimensional curved Lorentzian manifold called space-time. It is very important to recognize that this is NOT space and time it one thing, space-time, and it is not possible to separate the notions of space and time, except very locally. Basically space and time live on the tangent space, but on the manifold, which is the universe, space and time are all mixed together because of curvature.

In short there is no such thing as pure "time". This a terrible psychological problem because we all have an innate sense of Newton's flowing "river of time". The problem is that our innate sense is wrong. There is no viable fundamental definition of time that is not circular. We have operational definitions that are used to define the second very precisely, and those operational definitions are quite adequate for commerce and for exquisitely accurate scientific experiments. But they fall short of the clarity needed for a solid mathematical definition. We know what time is in a flat space, but in a curved space that includes gravity (and we rather need gravity) the definition falls apart. We are left with "time is what clocks measure". That is probably one of the major difficulties in formulating a fundamental theory that includes all of the known forces.

So what's the problem? Why do people want to know what "time" is? Is there any incentive to define "time"?




Why would anyone ask if someone like Einstein didn't think it was an issue?

So what einstein didn't think it was an issue, he might have missed it or skipped over it or thought he didn't find it interesting. Just because einstein may have thought it was irrelavent doesn't mean it is. He probably would have thought 'Computers, whats the point in them?'.
It really annoys me when people say things like 'Well einstein didn't think it was an issue' as if he is the god of all physics. He is not and he did get things wrong such as in his debates with Neils Bohr with him aguing against the probability factor of wuantum mechanics.
Einstein was just one physacist, maybe he just had to much on his plate, I don't know. But just because 'he didn't think of it' does not by all means make it irrelavent!

Originally Posted by Nevyn

So what einstein didn't think it was an issue, he might have missed it or skipped over it or thought he didn't find it interesting. Just because einstein may have thought it was irrelavent doesn't mean it is. He probably would have thought 'Computers, whats the point in them?'.
It really annoys me when people say things like 'Well einstein didn't think it was an issue' as if he is the god of all physics. He is not and he did get things wrong such as in his debates with Neils Bohr with him aguing against the probability factor of wuantum mechanics.
Einstein was just one physacist, maybe he just had to much on his plate, I don't know. But just because 'he didn't think of it' does not by all means make it irrelavent!

Yeah! I agree. So what if he didn't think about it? Why does everyone define worthy and 'not' worthy from what he thought? He didn't think that cars would catch on, and he thought that the evolving technology was a waste of time!

Originally Posted by Nevyn

So what einstein didn't think it was an issue, he might have missed it or skipped over it or thought he didn't find it interesting. Just because einstein may have thought it was irrelavent doesn't mean it is. He probably would have thought 'Computers, whats the point in them?'.
It really annoys me when people say things like 'Well einstein didn't think it was an issue' as if he is the god of all physics. He is not and he did get things wrong such as in his debates with Neils Bohr with him aguing against the probability factor of wuantum mechanics.
Einstein was just one physacist, maybe he just had to much on his plate, I don't know. But just because 'he didn't think of it' does not by all means make it irrelavent!

Ok, so what would defining "time" (as acutely as logic allows) prove? What would it lead to?

well I think that defining time has is foot in both philosophy and physics and the too should not be muddled up as they so often do. Like I said earlier the definition that I can come up with for time is "The flow of one 'snapshot' of the universe to the next". now if we were able to manipulate time if would be an immensly usefull thing even if we could only speed it up in the forwards direction. Imagine having a block of uranium and instanteously being able to extract all the energy from it at once...

Originally Posted by Nevyn

well I think that defining time has is foot in both philosophy and physics and the too should not be muddled up as they so often do. Like I said earlier the definition that I can come up with for time is "The flow of one 'snapshot' of the universe to the next". now if we were able to manipulate time if would be an immensly usefull thing even if we could only speed it up in the forwards direction. Imagine having a block of uranium and instanteously being able to extract all the energy from it at once...

So, are you suggesting that "time" is not a pure measurement device, but something that can be manipulated?

well how can you have a measurement with nothing from which it has been measured? sure time can be measured but if you are saying that it is purely a measurement then how could there have been time before it was measured?

Originally Posted by Nevyn

well how can you have a measurement with nothing from which it has been measured? sure time can be measured but if you are saying that it is purely a measurement then how could there have been time before it was measured?

You are measuring relative motion and calling it time.

[quote="(In)Sanity"]

A ship traveling at the speed of light that takes one earth year to reach it's destination did in fact take one year to do so. If the clock on the ship starts to fall behind the clock on the wall at mission control back on earth this would have to indicate that the matter and energy used to make the clock work has in fact slowed in it's cycles. The occupants of course would have no awareness of this unless they had some kind of link back to an external reference point.

You seem to be assuming that if the occupants did have a link back to the mission control clock that they would measure it as moving fast compared to their own. This is not the case. They would measure it as running slow compared to their own.

To explain the difference, let's use an analogy.

Imagine a 2-D plane. you have two observers traveling parallel to the y axis, and in this case the y axis is time. They each measure the passage of time as how far they travel along the y axis. Assuming that they travel at the same "speed" they progress through time at the same rate. (When each observer looks at the other he sees him as being an equal distance from the x axis as himself. IOW, as having aged the same) This respesents two observers at rest with respect to each other and aging at the same rate.

Now assume that one of the observers also adds a motion along the x axis. They both progress along the y axis at the same rate, but as they do so, they separate along the x axis. They still maintain the same distance from the x axis. This represents the two observers with a relative motion with respect to each other and don't age differently due to their relative motion.
This is how things were thought to be before Relativity.


Now assume that the observer with the x axis motion must maintain the same relative motion with respect to the origin as the other observer. In this case, the movment along the x axis come at the expense of movement along the y axis. Now the two observers no longer maintain the same distance from the x-axis. The one with the x axis motion always has traveled the least distance along the y axis. He still measures time as progress along the y axis, so he doesn't "notice" time progressing slower for him, but he would notice the other observer as progressing through time (Aging faster) than himself.

This last example is what I assume is the analogy to your example.

Now here is how Relativity handles it:

Again, our two observers with relative motion maintain the same speed relative to the "origin", but now, progress through time is not measured by distance along the y axis, but by distance traveled by the observer along the line of his own travel. For example, assuming that are observers start at the same point, As each observer progresses, he will note that the other observer will not have progressed as much as he has in the same direction as he himself is progressing. IOW, the other observer will progress through time (age slower) than he will.

At this point you may be asking: But if this is the case, how do we explain the "Twin paradox" where one twin actually returns younger than the other?

For this you have to imagine that one of our observers "turns" so that his new path intersects the other's. This is the same as the space twin stopping and heading back towards Earth.

From the other observer's point of view, this doesn't change much; just the fact that the distance between the two now starts to decrease. The observer that "turned" still ages slower, and when he intersects the other observers path, he will have still progressed a less amount through time and aged less. (when the two twins meet up, one will be younger).

But for the twin that "turns", something does change. He has changed the "direction" in which he measures progress through time, and as a result, the other twin's position in time in relation to him. (Imagine that you are facing North, and there is a landmark East by Southeast of you. This land mark will be behind you. Now turn to face Southeast. That same landmark will now be ahead of you.)
The other observer goes from being behind him in time progression (aged less) before the turn, to ahead of him in time progression(aged more) after the turn.

After he turns, the observer progresses until he intersects the other observers path, at which time he will still be "behind" him in time and have aged less.

Thus in Relativity, while the two observers will agree as to who aged less and by how much when they meet up again, at any other point, they will disagree,

Furthermore, each observer's version of what happened is just as valid as the other's. You cannot say that one is what "really" happened.

Originally Posted by KALSTER

Originally Posted by Nevyn

well how can you have a measurement with nothing from which it has been measured? sure time can be measured but if you are saying that it is purely a measurement then how could there have been time before it was measured?

You are measuring relative motion and calling it time.

I am not, I calling the changes in any quantaty be it velocity, energy, charge etc. time. if you take the universe now and the universe 5 seconds ago it will have changed the period between 5 seconds ago and now is time

At this point you may be asking: But if this is the case, how do we explain the "Twin paradox" where one twin actually returns younger than the other?

For this you have to imagine that one of our observers "turns" so that his new path intersects the other's. This is the same as the space twin stopping and heading back towards Earth.

From the other observer's point of view, this doesn't change much; just the fact that the distance between the two now starts to decrease. The observer that "turned" still ages slower, and when he intersects the other observers path, he will have still progressed a less amount through time and aged less. (when the two twins meet up, one will be younger).

In the end any theory like this has to relate back to what effects on physical matter and/or energy produced such a result. Time is not a real object. It's simply change in matter or energy in relation to other change in matter or energy. So any time one refers to time speeding up or slowing down in any fashion you have to be saying that the matter and or energy in that scope is in fact changing it's cyclic relationships relative to some external reference. I think time has been over glorified to the point where people start to think of it as an object.

So given some of your examples how would you express them in terms of changes in matter and energy. In order for one clock to differ from another clock the mechanisms that allow the clock to function must have altered in a physical sense. We have absolutely no other frame of reference of "time" other then changes in our physical world. One can't say the clock lost an hour because "time" slowed down. One can say the sub atomic oscillations of the nuclear clock slowed in reference to the other nuclear clock causing a difference in measurement between the two. Any of these theories always has to relate back to physical matter. I just don't see any possible way around this. Unless of course these theories refer to some magical mystical force that we have absolutely no knowledge of.

What if you said that time was an energy, end the more energy you put into movement, the less energy you spent on time? This would explain how the moving twins' 'time' slowed down and he aged less.

That means that the definition of time would be: an energy field around us which we manipulate into a a sense of progression through a sequence of events.

Originally Posted by (In)Sanity

In the end any theory like this has to relate back to what effects on physical matter and/or energy produced such a result. Time is not a real object. It's simply change in matter or energy in relation to other change in matter or energy. So any time one refers to time speeding up or slowing down in any fashion you have to be saying that the matter and or energy in that scope is in fact changing it's cyclic relationships relative to some external reference. I think time has been over glorified to the point where people start to think of it as an object.

So given some of your examples how would you express them in terms of changes in matter and energy. In order for one clock to differ from another clock the mechanisms that allow the clock to function must have altered in a physical sense. We have absolutely no other frame of reference of "time" other then changes in our physical world. One can't say the clock lost an hour because "time" slowed down. One can say the sub atomic oscillations of the nuclear clock slowed in reference to the other nuclear clock causing a difference in measurement between the two. Any of these theories always has to relate back to physical matter. I just don't see any possible way around this. Unless of course these theories refer to some magical mystical force that we have absolutely no knowledge of.

In one sense, time was simply another variable in the way that physics looks at the world in mathematical terms. However, physics is always rooted in observational measurements and so the use of clocks are a way of measuring this parameter. On the other hand, we see a progression to more accurate measuring devices for time because time is not really defined by any measuring device per se, and thus we do see that we have some sort of abstract ideal which the measuring devices give us concrete access to.

Finding a right balance between abstract ideal and measurements was one of the first hurdles in the development of modern physics - learning to ignore details at first in order to see the underlying pattern and only then using that pattern as a means to analyze the details.

Einstein certainly made an important advance beyond our assumptions about time by refering time back to clocks. On the other hand, these clocks were most of the time abstract mathematical ideals rather than actual physical clocks.

Originally Posted by (In)Sanity

In the end any theory like this has to relate back to what effects on physical matter and/or energy produced such a result. Time is not a real object. It's simply change in matter or energy in relation to other change in matter or energy. So any time one refers to time speeding up or slowing down in any fashion you have to be saying that the matter and or energy in that scope is in fact changing it's cyclic relationships relative to some external reference. I think time has been over glorified to the point where people start to think of it as an object.

Neither time nor space are "real objects" in the sense in which you are using the words.

Time is certainly measured using changes in matter or energy. But that is quite different from defining time to actually BE changes in matter or energy. If you think you can so define time then please define "one second" in those terms without using the word "time".

Originally Posted by (In)Sanity

So given some of your examples how would you express them in terms of changes in matter and energy. In order for one clock to differ from another clock the mechanisms that allow the clock to function must have altered in a physical sense. We have absolutely no other frame of reference of "time" other then changes in our physical world. One can't say the clock lost an hour because "time" slowed down. One can say the sub atomic oscillations of the nuclear clock slowed in reference to the other nuclear clock causing a difference in measurement between the two. Any of these theories always has to relate back to physical matter. I just don't see any possible way around this. Unless of course these theories refer to some magical mystical force that we have absolutely no knowledge of.

This is precisely correct. The sub-atomic oscillations constitute a "clock", and time is "what clocks measure". There is no meaning to the statement that "time slows down" (how can you measure a rate of time or anything else without a notion of time to start with) there is only meaning to a comparision of the measurements of two clocks. Relativity tells you how to compare the measurements made by two clocks in relative motion with respect to one another. It is no help whatever in providing a fundamental definition of "time" (unless you find defining it as the eigenvector corresponding to + in the standard Minkowski 2-form (+,-,-,-) satisfying -- I don't).

In GR you don't even have a means of defining "time" in the usual sense. Time, like everything else is dependent on particular world lines. You can only compare what two observers see when they end up at the same point in space-time and you compare the world lines that allowed them to reach those points. In particular in the "twin paradox", in GR, you only get to make comparisions upon the completion ot the journey when the twins are re-united.

Originally Posted by (In)Sanity

So given some of your examples how would you express them in terms of changes in matter and energy. In order for one clock to differ from another clock the mechanisms that allow the clock to function must have altered in a physical sense. We have absolutely no other frame of reference of "time" other then changes in our physical world. One can't say the clock lost an hour because "time" slowed down. One can say the sub atomic oscillations of the nuclear clock slowed in reference to the other nuclear clock causing a difference in measurement between the two. Any of these theories always has to relate back to physical matter. I just don't see any possible way around this. Unless of course these theories refer to some magical mystical force that we have absolutely no knowledge of.

The most common example would be the light clock:

Two parallel mirrors spaced a distance apart with a light pulse reflecting back and forth between them. Each round trip represents 1 "tick" of the clock.

We place two light clocks in relative motion with respect to each other with their motion along a line perpendicular to the spacing of the mirrors:



The red numerals count the "ticks" of each clock.

Given that the speed of light is a constant, as shown by the expanding circles in the image, this means that the pulse for the clock shown as moving in this image takes longer to make one round trip between the mirrors. Therefore it ticks once for every 2 ticks of the clock shown as stationary.

If however, we were traveling with the moving clock, we would only see our pulse go back and forth between the mirrors, and since the speed of light is also a constant for us, we judge the interval between two ticks as being the same as if the clock were "stationary".(We can't tell if our clock was moving by the interval between ticks.) In addition, since from our perspective, it is the other clock that is moving, it is its light pulse that takes longer to make the round trip and it is the one that only ticks once for every two ticks of our clock.

So if you were looking for a "physical" cause for one clock to differ from the other, it is the constancy of the speed of light. But since each clock measures the speed of light as a constant relative to itself, each clock finds that it is the other clock that runs slow compared to itself. The "physical" cause only acts on systems that have a relative motion with respect to us.

Given that the speed of light is a constant, as shown by the expanding circles in the image, this means that the pulse for the clock shown as moving in this image takes longer to make one round trip between the mirrors. Therefore it ticks once for every 2 ticks of the clock shown as stationary.

If however, we were traveling with the moving clock, we would only see our pulse go back and forth between the mirrors, and since the speed of light is also a constant for us, we judge the interval between two ticks as being the same as if the clock were "stationary".(We can't tell if our clock was moving by the interval between ticks.) In addition, since from our perspective, it is the other clock that is moving, it is its light pulse that takes longer to make the round trip and it is the one that only ticks once for every two ticks of our clock.

Hmm, I'm still trying to get this.

Perhaps I'm not understanding what the theory on the twins is really getting to. Let's say (and please correct me if I'm off base) two people of the same age left earth at the same moment and headed off to the exact same point in space. We'll call the first one Jack and say he traveled at 0.5C to this distant place. We'll call the second Jill and say she headed off at 1.0C. We'll say the earth has to rotate around the sun once and Jill will be at her destination and start the return trip home. Jack traveling slower will reach the destination on the second revolution of the earth around the sun and Jill will be already home and back in her condo eating bonbon's. On the forth trip of the earth around the sun Jack returns home and joins Jill at her condo and unfortunately she's now 350 lbs. The question is how much older or younger is Jack from Jill. Logic says they have to be the same age.

If you think you can so define time then please define "one second" in those terms without using the word "time".

When the wheel on the generator at the power plant rotates 360 degrees for a total count of 60. When my ceiling fan over my head travels 52 degrees.

What's a year, well it's when the earth travels around the sun one time and ends at it's starting point. What's a day, it's when the earth rotates 360 degrees or one full circle. What's a second in deep space far far away from pretty much all matter and energy? It would be pretty hard to figure that one out, Perhaps we could just say it's when that distant star blinks 47 times or maybe that other one over there as we like it a little better. So long as we keep using the same reference points it really doesn't matter.

Originally Posted by (In)Sanity

Perhaps I'm not understanding what the theory on the twins is really getting to. Let's say (and please correct me if I'm off base) two people of the same age left earth at the same moment and headed off to the exact same point in space. We'll call the first one Jack and say he traveled at 0.5C to this distant place. We'll call the second Jill and say she headed off at 1.0C. We'll say the earth has to rotate around the sun once and Jill will be at her destination and start the return trip home. Jack traveling slower will reach the destination on the second revolution of the earth around the sun and Jill will be already home and back in her condo eating bonbon's. On the forth trip of the earth around the sun Jack returns home and joins Jill at her condo and unfortunately she's now 350 lbs. The question is how much older or younger is Jack from Jill. Logic says they have to be the same age.

This is impossible because no massive object can travel at 1.0 c. Lets change this Jills speed to .9897 c as in Janus' example. Furthermore you have over specified the problem by giving their velocities, time and that they travel the same distnace, so lets change this to make their destinations different.

Now if you define their ages according to the the revolutions of the earth around the sun then what you say is true. But if you define it according to clocks they carry with them (including their "biological clocks") then this is not true. For .5c the time dilation factor gamma is only 1.155 and for .9897 c the time dilation factor is 7.0, so at the end of four years Jills clocks will have advanced by 2years/7.0(on ship) + 2years(on earth) = 2.2857 years and Jacks clocks will have advanced by 4years/1.155 = 3.463 years.

Originally Posted by (In)Sanity

Hmm, I'm still trying to get this.

Perhaps I'm not understanding what the theory on the twins is really getting to. Let's say (and please correct me if I'm off base) two people of the same age left earth at the same moment and headed off to the exact same point in space. We'll call the first one Jack and say he traveled at 0.5C to this distant place. We'll call the second Jill and say she headed off at 1.0C. We'll say the earth has to rotate around the sun once and Jill will be at her destination and start the return trip home. Jack traveling slower will reach the destination on the second revolution of the earth around the sun and Jill will be already home and back in her condo eating bonbon's. On the forth trip of the earth around the sun Jack returns home and joins Jill at her condo and unfortunately she's now 350 lbs. The question is how much older or younger is Jack from Jill. Logic says they have to be the same age.

But this example doesn't deal with Relativity or the Twin paradox all. It describes a non-relativistic universe. In Relativity, Jill traveling at 0.9897c (as suggested) would only experienced about 14 weeks and 6 days as measured by her own local time while the Earth makes its two trips around the Sun, and Jack will have experienced about 3 years, 24 weeks and 1 day in while the Earth makes 4 trips.

Thus when Jack and Jill meet up again, Jill will have personally experienced and aged 2 years, 14 weeks and 6 days (two of those years eating Bon Bons waiting for jack to return), while Jack will have personally experienced and aged 3 years, 24 weeks and 1 day.

In Relativity, observers with relative motion with respect to each other will measure the same interval between two events differently according to their own local means of measuring time.

Thus when Jack and Jill meet up again, Jill will have personally experienced and aged 2 years, 14 weeks and 6 days (two of those years eating Bon Bons waiting for jack to return), while Jack will have personally experienced and aged 3 years, 24 weeks and 1 day.

Ok, so what your saying is that Jack and Jill both had a slowing of their molecular structure (along with their clocks) in order to achieve this lesser aging.

One possible way I see it is that the sub atomic interactions lets say for example an electron flying around the nucleus of an atom can't exceed the speed of light. So the closer one would get to the speed of light the more hindered that electron would be to travel at it's full speed. Think of it as a flywheel on board a spaceship that is traveling at a rotational velocity of 1000 feet per second. This flywheel would be able to maintain it's forward velocity up until it got very close to the speed of light at which point it couldn't achieve 1000 fps + C. It in theory should stop moving at C. Assuming of course it's traveling in the exact same direction. I see the molecular structure of Jack and Jill doing the same thing. I'm of course just speculating on this.

If I'm way off base I would love to hear a real world explanation as to why they aged differently. So far I've not heard of a reason that deals with reality, only mathematical possibility.

Originally Posted by (In)Sanity

Ok, so what your saying is that Jack and Jill both had a slowing of their molecular structure (along with their clocks) in order to achieve this lesser aging.

One possible way I see it is that the sub atomic interactions lets say for example an electron flying around the nucleus of an atom can't exceed the speed of light. So the closer one would get to the speed of light the more hindered that electron would be to travel at it's full speed. Think of it as a flywheel on board a spaceship that is traveling at a rotational velocity of 1000 feet per second. This flywheel would be able to maintain it's forward velocity up until it got very close to the speed of light at which point it couldn't achieve 1000 fps + C. It in theory should stop moving at C. Assuming of course it's traveling in the exact same direction. I see the molecular structure of Jack and Jill doing the same thing. I'm of course just speculating on this.

If I'm way off base I would love to hear a real world explanation as to why they aged differently. So far I've not heard of a reason that deals with reality, only mathematical possibility.

The problem with that example is this:
I assume that you mean that the axis of the flywheel is perpendicular to the motion of the spaceship. Thus one edge of the flywheel is moving at 1000 fps relative to the ship in the direction of the bow.

But what if you have a second flywheel rotatig at the same speed relative to the ship but with its axis parallel to the ship's motion? Then then relative to a observr watching the ship go by the edge woud not be moving at the ship's velocity +1000 fps but at the squareroot of the sum of the squares of the ships velocity and 1000 fps. This is smaller than the relative speed of the edge of the other flywheel, so it wouldn't be effected until the ship got much closer to the speed of light. So this flywheel would slow less than the other flywheel.
But to someone in the ship, both flywheels should spin at the same speed.

The second problem is, at close to the speed of light relative to what? I get this feeling that you are holding on to the idea that there is some fixed absolute reference of absolute rest that motion can be judged by.

Originally Posted by (In)Sanity

Thus when Jack and Jill meet up again, Jill will have personally experienced and aged 2 years, 14 weeks and 6 days (two of those years eating Bon Bons waiting for jack to return), while Jack will have personally experienced and aged 3 years, 24 weeks and 1 day.

Ok, so what your saying is that Jack and Jill both had a slowing of their molecular structure (along with their clocks) in order to achieve this lesser aging.

One possible way I see it is that the sub atomic interactions lets say for example an electron flying around the nucleus of an atom can't exceed the speed of light. So the closer one would get to the speed of light the more hindered that electron would be to travel at it's full speed. Think of it as a flywheel on board a spaceship that is traveling at a rotational velocity of 1000 feet per second. This flywheel would be able to maintain it's forward velocity up until it got very close to the speed of light at which point it couldn't achieve 1000 fps + C. It in theory should stop moving at C. Assuming of course it's traveling in the exact same direction. I see the molecular structure of Jack and Jill doing the same thing. I'm of course just speculating on this.

If I'm way off base I would love to hear a real world explanation as to why they aged differently. So far I've not heard of a reason that deals with reality, only mathematical possibility.

Perhaps it would help to see it this way: This really isn't a velocity limitation but how the structure of space time effects how relative velocity is measured. The speed of light really is an infinite velocity -- a rocket (with an infinite supply of fuel) would after all require an infinite amount of time to "reach" that velocity and it can reach a destination as quickly as it likes by going fast enough. It is just that other observers see this infinite velocity as the speed of light.

Originally Posted by (In)Sanity

If you think you can so define time then please define "one second" in those terms without using the word "time".

When the wheel on the generator at the power plant rotates 360 degrees for a total count of 60. When my ceiling fan over my head travels 52 degrees.

What's a year, well it's when the earth travels around the sun one time and ends at it's starting point. What's a day, it's when the earth rotates 360 degrees or one full circle. What's a second in deep space far far away from pretty much all matter and energy? It would be pretty hard to figure that one out, Perhaps we could just say it's when that distant star blinks 47 times or maybe that other one over there as we like it a little better. So long as we keep using the same reference points it really doesn't matter.

Sorry, no cigar. You simply subsituted "when" for "time".

Your definition is operational, and is simply saying, once again, that time is what clocks measure. In this case you are simply using the earth, , the wheel on your generator, or the ceiling fan as a clock.

This is understandable. No one has ever given a definition of time other than in such an operational manner. Your definition sufficies to determine the "length" of "one second" but it does not give a fundamental defninition of what time is. You are right back to "time is what clocks measure". And that is all that special relativity does -- it gives you a way to compare clocks in uniform motion relative to one another.

It is also important to recognzie that special relativity only applies in an inertial reference frame. If you try to apply the equations or basic reasoning in a non-inertial reference frame you get nonsense -- like the twin paradox.

The second problem is, at close to the speed of light relative to what? I get this feeling that you are holding on to the idea that there is some fixed absolute reference of absolute rest that motion can be judged by.

Yes that actually might be my misunderstanding. I guess if I asked the old question of if your in a train going at the speed of light and you walked forward are you going faster then the speed of light.

The other question still remains that how can traveling at a great velocity impact clocks and people on board a ship in such a way that they age slower. In my mind I have to conclude that matter and energy are impacted to cause their molecular structure to age slower and the clock to "tick" slower. I have a very hard time thinking outside of what I consider logical. Granted of course that from time to time my logic is flawed.

Originally Posted by DrRocket

Originally Posted by (In)Sanity

If you think you can so define time then please define "one second" in those terms without using the word "time".

When the wheel on the generator at the power plant rotates 360 degrees for a total count of 60. When my ceiling fan over my head travels 52 degrees.

What's a year, well it's when the earth travels around the sun one time and ends at it's starting point. What's a day, it's when the earth rotates 360 degrees or one full circle. What's a second in deep space far far away from pretty much all matter and energy? It would be pretty hard to figure that one out, Perhaps we could just say it's when that distant star blinks 47 times or maybe that other one over there as we like it a little better. So long as we keep using the same reference points it really doesn't matter.

Sorry, no cigar. You simply subsituted "when" for "time".

Your definition is operational, and is simply saying, once again, that time is what clocks measure. In this case you are simply using the earth, , the wheel on your generator, or the ceiling fan as a clock.

This is understandable. No one has ever given a definition of time other than in such an operational manner. Your definition sufficies to determine the "length" of "one second" but it does not give a fundamental defninition of what time is. You are right back to "time is what clocks measure". And that is all that special relativity does -- it gives you a way to compare clocks in uniform motion relative to one another.

It is also important to recognzie that special relativity only applies in an inertial reference frame. If you try to apply the equations or basic reasoning in a non-inertial reference frame you get nonsense -- like the twin paradox.

It's funny I went to bed and knew you would respond this way. I was thinking that I used the word "when" and you would equate that to time. In reality I could have just said "60 rotations of a generator flywheel at a power plant" and skipped the when. I don't see time as being anything else but the movement of the physical universe we live in and thus it's impossible to define time without some form of movement and or count of cyclic movement. Language and imaginations have also skewed the definition of time to the point where some people just don't get it.

Originally Posted by (In)Sanity

The second problem is, at close to the speed of light relative to what? I get this feeling that you are holding on to the idea that there is some fixed absolute reference of absolute rest that motion can be judged by.

Yes that actually might be my misunderstanding. I guess if I asked the old question of if your in a train going at the speed of light and you walked forward are you going faster then the speed of light.

The train can't be going the speed of light in the first place. Also, if the train were going .6c relative to the ground and you were going .6c relative to the train, you'd only be going about .88c relative to the ground, not 1.2c.

Originally Posted by (In)Sanity

The other question still remains that how can traveling at a great velocity impact clocks and people on board a ship in such a way that they age slower.

It doesn't. This is not an effect on the those traveling any more or less than it is an effect on those who stay behind. Remember who is traveling is relative question.

Originally Posted by (In)Sanity

In my mind I have to conclude that matter and energy are impacted to cause their molecular structure to age slower and the clock to "tick" slower.

But this is completely incorrect. Consider again the ship traveling away from the earth at .9897 c: In our example we came to the conclusion that at the end of the trip the passage of time on the ship would be one seventh as fast as the clocks on the earth. BUT, does this mean that the speed of the ship is affecting the speed of the molecules in the ship so that time is slower on the ship? NO!!! How do I know? Why because of this simple fact, if the earth had engines of its own and accelerated to the same speed as the ship and then they compared their clocks we would find out that the opposite is the case and that it is the clocks on the earth that were running one seventh as fast as the clocks on the ship, while they were supposedly NOT MOVING.

You must never forget that in relativity, velocity is always completely relative. If the ship is traveling .9897 c away from the earth then the earth is also traveling .9897 c away from the ship. There is no absolute velocity to say that one is moving and the other is not moving. Both see the same length contraction and time dilation in the OTHER guy. Who turns out to "be right" depends on whose inertial frame you end up in when make a comparison. Or to be more precise, those who change what inertial frame they in are the ones that have to change how they measure space and time.

Originally Posted by (In)Sanity

Yes that actually might be my misunderstanding. I guess if I asked the old question of if your in a train going at the speed of light and you walked forward are you going faster then the speed of light.

The other question still remains that how can traveling at a great velocity impact clocks and people on board a ship in such a way that they age slower. In my mind I have to conclude that matter and energy are impacted to cause their molecular structure to age slower and the clock to "tick" slower. I have a very hard time thinking outside of what I consider logical. Granted of course that from time to time my logic is flawed.

Here's the thing: Relativity is perfectly logical, but it is non-intuitive. It is your intuition that is giving you problems not your logic. Your intuition(And that of most people) is telling you that the universe behaves like "X". Following valid logic based on "X" leads you to certain conclusions. Relativity, however, says that the Universe behaves like "Y", Applying valid logic based on "Y" leads to different conclusions.

Every experiment performed to date to test between "X" and "Y" has come down in the favor of "Y".

If this is the case, then why is it that your intuition is telling you "X" When "Y" is reality? The reason is that at under the conditions we normal experience,(low relative speeds) "Y" is pretty much indistinguishable from "X". For example, "X" says that to add two velocities you use v+u, while "Y" says that you need to use



So if we add 50 m/s and 50 m/s, "X" says we get 100 m/s and "Y" says we get 99.99999999999997222222222222223... m/s A difference of only ~28 femtometers/sec. (a Helium atom is about 62000 femtometers across.)

Since it is easier to think in terms of u+v, this is how we naturally tend to think the universe behaves.

Originally Posted by (In)Sanity

It's funny I went to bed and knew you would respond this way. I was thinking that I used the word "when" and you would equate that to time. In reality I could have just said "60 rotations of a generator flywheel at a power plant" and skipped the when. I don't see time as being anything else but the movement of the physical universe we live in and thus it's impossible to define time without some form of movement and or count of cyclic movement. Language and imaginations have also skewed the definition of time to the point where some people just don't get it.

The point is not that you are wrong.

The point is that NO ONE has ever been able to define "time" in any manner other than an operational manner that ends up being "time is what clocks measure".

You are probably right. Time has something to do with the change in the state of matter-energy. But there is simply no useful definition that has ever been formulated that makes this idea precise -- precise enough for use in formulating physical theories.

IF you could give a useful definition of time in other than an operational manner, then you could probably also, from that definition be able to determine why time seems to progress in only one direction, and why we see time progressing in only that direction despite the fact that the equations of physics are symmetric and would seem to allow time to progress toward the past as well as the future. This is one of the major mysteries in physics.

If you could actually give a definition of time and back it up, you would likely be a candidate for a Nobel prize, at least.

You are trying to use your ordinary experience to understand relativity. That won't work. It is not a problem of logic. If that is all that was involved, then it would not have taken an Einstein to formulate the theory. The theory is actually very logical. It can be deduced using ordinary logic, based on two axioms. Those axioms are 1) the speed of light is constant in all inertial reference frames and 2) the laws of physics are the same in all inertial reference frames. The kicker is that axiom 1 is not at all intuitive and it violates your everyday experience. Your everyday experience would tell you that if someone on a train traveling at 100 mph toward you shined a flashlight toward you the beam of light would travel at c + 100 mph, but that is not what happens it travels toward you at c and the guy on the train also see it leaving him at c. This is not all intuitive. It does not matter that this violates your intuition (or your everyday "logic"), because it has been confirmed by a host of experiments.

Physics is quite logical. But it is not intuitive. If you think relativity is weird, then just wait until you take a close look at quantum mechanics. QM is also logical, but only in terms of following logically from a set of axioms, and those axioms lead to some things that are really strange.

You are trying to use your ordinary experience to understand relativity. That won't work. It is not a problem of logic. If that is all that was involved, then it would not have taken an Einstein to formulate the theory. The theory is actually very logical. It can be deduced using ordinary logic, based on two axioms. Those axioms are 1) the speed of light is constant in all inertial reference frames and 2) the laws of physics are the same in all inertial reference frames. The kicker is that axiom 1 is not at all intuitive and it violates your everyday experience. Your everyday experience would tell you that if someone on a train traveling at 100 mph toward you shined a flashlight toward you the beam of light would travel at c + 100 mph, but that is not what happens it travels toward you at c and the guy on the train also see it leaving him at c. This is not all intuitive. It does not matter that this violates your intuition (or your everyday "logic"), because it has been confirmed by a host of experiments.

I guess what it really boils down to for me at least is has anyone proven these theories accurate and if so what mechanisms on a molecular level are causing changes in measured time.

Some of this stuff is like saying, see that guy over there he left a year ago. He doesn't however know he was gone a year and that his birthday is really tomorrow. The watch on his wrist is the most accurate made and well it's off by 6 months. Logic tells me that these things can only happen if in his little journey matter and energy changed in such a way to cause him to age less and his watch to tick slower then back on earth.

Let's say for example that we created artificial intelligence inside of a computer that was only aware of it's environment inside the computer and nothing else. Inside this AI's world are many clocks that all appear to be pretty accurate from it's prospective. What the AI life form isn't aware of however is that we keep pausing the program and speeding it up and slowing it down. From the AI's point of view absolutely nothing has changed and the world keeps ticking along with perfection. From our point of view many weeks might go by on our clocks vs the clocks inside the AI's world. Once in a while we'll speed up the computer and make the AI's clocks tick at the same rate as our clocks. Most of the time we are constantly changing the speed of the computer to make small adjustments in the environment or just to observe things a little better. Again to the AI's world nothing has changed, an hour still seams like an hour.

So using the above analogy what is speeding up or slowing down to cause the traveler to feel as if nothing is different yet to the outside far more time has passed. That's really the only question I'm still trying to find an answer to with this theory.

What actually happens when you leave the earth at nearly the speed of light? What makes your motion relative to the people on earths' motion so different?
Why is it slowed down 7 times when you travel at 0.9897c ?
Is there some way to calculate how much 'your time' would 'slow' relative to 'the earth's time'?

I give up.

Originally Posted by (In)Sanity

You are trying to use your ordinary experience to understand relativity. That won't work. It is not a problem of logic. If that is all that was involved, then it would not have taken an Einstein to formulate the theory. The theory is actually very logical. It can be deduced using ordinary logic, based on two axioms. Those axioms are 1) the speed of light is constant in all inertial reference frames and 2) the laws of physics are the same in all inertial reference frames. The kicker is that axiom 1 is not at all intuitive and it violates your everyday experience. Your everyday experience would tell you that if someone on a train traveling at 100 mph toward you shined a flashlight toward you the beam of light would travel at c + 100 mph, but that is not what happens it travels toward you at c and the guy on the train also see it leaving him at c. This is not all intuitive. It does not matter that this violates your intuition (or your everyday "logic"), because it has been confirmed by a host of experiments.

I guess what it really boils down to for me at least is has anyone proven these theories accurate and if so what mechanisms on a molecular level are causing changes in measured time.

Some of this stuff is like saying, see that guy over there he left a year ago. He doesn't however know he was gone a year and that his birthday is really tomorrow. The watch on his wrist is the most accurate made and well it's off by 6 months. Logic tells me that these things can only happen if in his little journey matter and energy changed in such a way to cause him to age less and his watch to tick slower then back on earth.

Let's say for example that we created artificial intelligence inside of a computer that was only aware of it's environment inside the computer and nothing else. Inside this AI's world are many clocks that all appear to be pretty accurate from it's prospective. What the AI life form isn't aware of however is that we keep pausing the program and speeding it up and slowing it down. From the AI's point of view absolutely nothing has changed and the world keeps ticking along with perfection. From our point of view many weeks might go by on our clocks vs the clocks inside the AI's world. Once in a while we'll speed up the computer and make the AI's clocks tick at the same rate as our clocks. Most of the time we are constantly changing the speed of the computer to make small adjustments in the environment or just to observe things a little better. Again to the AI's world nothing has changed, an hour still seams like an hour.

So using the above analogy what is speeding up or slowing down to cause the traveler to feel as if nothing is different yet to the outside far more time has passed. That's really the only question I'm still trying to find an answer to with this theory.

OK try this.

Relativity is a somewhat abstract theory. It is fundamentally a new theory of space and time.

There is NOTHING going on at a molecular level or any other level in the molecules of something that is moving to cause the processes to slow down. In fact they do not slow down. An observer A at rest in the reference frame that is moving with respect to observer B sees NOTHING unusual. His clock, to him, just keeps right on ticking like the proverbial Timex. It is only observer B who sees that A's clock runs more slowly than his own clock. Conversely observer A sees B's clock as being slow relatively to his own clock. It is completely symmetric.

The twin paradox is another kettle of fish entirely.

There are several resolutions. ALL of them show that the traveling twin, on return from the trip, has recorded less time than the stay-at-home twin. To completely explain the phenomena you need general relativity. The problems that you are having with special relativity will be magnified and debilitating in a discussion of general relativity.

The resolution in terms of special relativity is simple. Special relativity only applies in an inertial reference frame. In the "twin paradox" there is only one inertial reference frame, and it is that of the stay-at-home twin. If you use his reference frame it is clear that the traveling twin has aged less. This has been proved in direct experiments in which atomic clocks were flown around in jet aircraft.

The atomic clock experiment and a mountain of other experiments have shown the theory of relativity to be exquisitely accurate. Those same experiments have shown that "common sense" is worthless.

http://en.wikipedia.org/wiki/Pound-Rebka_experiment

http://en.wikipedia.org/wiki/Tests_o...ral_relativity

http://en.wikipedia.org/wiki/Rossi-Hall_experiment

http://en.wikipedia.org/wiki/Kennedy...ike_experiment

http://en.wikipedia.org/wiki/Special_relativity



Bottom line : your logic is not logical. Physics doesn't work that way. It doesn't matter that "common sense" tells you that this can't happen Common sense is not worh anything in this case. The problem that you are having is precisely the problem and the approach that was taken by Aristotle and his Greek school of philosophers -- it held back the progress of science for centuries.

This appears to shed some light on my question.

http://en.wikipedia.org/wiki/Gravita..._time_dilation

Originally Posted by (In)Sanity

This appears to shed some light on my question.

http://en.wikipedia.org/wiki/Gravita..._time_dilation

That article is a discussion of the effect of space-time curvature, aka gravity, on time. It has been confirmed through the Pound-Rebka experiment (see the list of links that I supplied above), and is one of many confirmations of the predictions of general relativity.

However, it does not explain the time dilation of special relativity. Special relativity is "special" because it applies only in the absence of gravity, or equivalently only in flat space-time. In particular the effect of gravity on time is specifically excluded from the special theory.

It is a bit interesting that you find solace in general relativity and the effects of space-time curvature. One thing that you find from general relativity and the effect of curvature is that there is NO universal definition of time or of space. Curvature causes the concepts to be "mixed together" and eliminates the possibility of having global coordinates. One result of this lack of global coordinates (you have to use the full theory of differential manifolds which use "charts" which are only local) is that there is no notion of time that applies to distant regions of the universe, nor a clear notion of space either. Basically both space and time are illusory. So rather than clarifying the nature of "time" it really says that there is no such thing, except locally in terms of local clocks.

The problem with defining time also applies to defining space. Think about it deeply and you will find that it just as difficult (impossible?) to define "distance" abstractly as it is to define "time" abstractly, Just as it is easy to define what a "second" is in terms of the action of some periodic phenomena -- swings of a pendulum or oscillations of a cesium atom, it is easy to define a "meter" in terms of the destance between marks on a carefully controlled rod or the number of wavelengths of a particular frequency of light. But you will be hard pressed to define "distance" (hence space) or "time" in a clear manner without recourse to such operational definitions. General relativity goes even further and shows that these notions are purely local, and that you cannot, even in principle define them clearly and unambiguously everywhere in the universe -- I started to say "simultaneously" but there is no meaning to something being "simultaneous" throughout the universe.

Originally Posted by (In)Sanity

So using the above analogy what is speeding up or slowing down to cause the traveler to feel as if nothing is different yet to the outside far more time has passed. That's really the only question I'm still trying to find an answer to with this theory.

Here's the problem with that question. It is like asking, "If the world is round, what keeps the people on the underside from falling off?" It implies something about the nature of things. With the world question it is that "down" is a universal direction.

With your question, it is that "what is speeding up or slowing down" is universal (IOW everyone agrees as to whose clock is running slower of the two). For instance, say you have two identical clocks, one moving relative to the other. When clock A reads 4:00, someone next to A at that instant would say that clock B reads 2:00, And conversely, someone next to B at the instant it reads 2:00 would say that clock A at that same instant reads 4:00. This assumes that the relative difference between the clock readings is something that everyone will agree to.

But with Relativity, you can not make this assumption. In Relativity is very possible for clock A to say that Clock B reads 2:00 when it itself reads 4:00, and for Clock B to say that Clock A reads 1:00 when it itself reads 2:00.

To see how this can be, let's forget about clocks ticking slower or faster than each other and consider the following scenario:

You have two observers, A and B. They each have some method of keeping track of their own time. (it could be a clock, it could be counting heartbeats or it could be "one potato", two potato"). We don't care whether A and B use the same method or how A's method compares to B's, all we care about is that each has can tell one "moment" from another.

A is carrying a rod from the middle, such that he is exactly the same distance from either end. A and B have a relative motion to each other along a line that parallels the length of the rod. A and B pass right past each other, and at that instant, a flash of light is emitted the very spot at which they pass. When this happens, Since B is right next to A, he is also halfway between the two ends of the rod.

Now we apply the second postulate of SR to this situation. since both A and B must measure the speed of light as a constant, each sees the Light flash expand out at c in sphere at which he himself is at the center.

For A this means that since the ends of the rod are always an equal distance from him, the flash reaches both ends of the rod at the same time (say at the moment A counts "4 potato").

But For B something else happens. After one heartbeat, the light flash has expanded an equal distance from him in all directions, But the ends of the rod are not an equal distance from him anymore. The "leading" end of the rod has moved further away and the "trailing" end has moved closer. After the Second heartbeat the flash has expanded larger, and the leading end has moved further away and the trailing end closer. At the third heartbeat, the trailing end has reached the same distance from him as the light has expanded to; the trailing end and the light flash meet. However, the leading end has moved further away than the flash has expanded and the light has not reached it yet. B has to wait until the 5th heartbeat for the light to catch up to the leading end of the rod.

This means that the same events that happened at the same moment for A, happen at different moments according to B. Note that this has nothing to do with anything affecting the rate at Which A or B counts time.

This is the Relativity of Simultaneity, and if you can come to grips with this, you will have come a long way towards understanding how two clocks can tick at different rates without being effected by a "physical cause".

This is the Relativity of Simultaneity, and if you can come to grips with this, you will have come a long way towards understanding how two clocks can tick at different rates without being effected by a "physical cause".

Hmm, but without physical cause it becomes kinds of a "so what" kind of theory. Until one can understand why something works it's more difficult to accept that it just does. I'm not saying these theories have not been proven enough to warrant their validity, I'm just saying that it sure would be nice to understand the physical effects that are in play when these theories are tested. I know they did the whole test with the two nuclear clocks and the planes and ended up with them off by one second or something. I just question why is this and not that it just is.

If an electron orbits the nucleus of an atom at some point it will be in opposition to it's forward motion. Is it possible this opposition causes a slowing effect of the electron rotating around the atom ? Perhaps even causing it to drift a bit off course. Is it possible that the speed causes some form of gravitational effect that causes nearby atoms to be impacted in some way? These are the kind of questions I'm trying to answer. Knowing that something happens is nowhere near as much fun as knowing why. I realize many of you are wondering why I'm asking such silly questions, for me it's just a quest for understanding. The two planes and the two nuclear clocks would be a good model for me as they are based on slower speeds and exist on the earth.

Originally Posted by (In)Sanity

Hmm, but without physical cause it becomes kinds of a "so what" kind of theory. Until one can understand why something works it's more difficult to accept that it just does.

Do you understand why inertia exists? And if not, does this lack of understanding make it difficult to accept it?

I'm not saying these theories have not been proven enough to warrant their validity, I'm just saying that it sure would be nice to understand the physical effects that are in play when these theories are tested. I know they did the whole test with the two nuclear clocks and the planes and ended up with them off by one second or something. I just question why is this and not that it just is.

If an electron orbits the nucleus of an atom at some point it will be in opposition to it's forward motion. Is it possible this opposition causes a slowing effect of the electron rotating around the atom ? Perhaps even causing it to drift a bit off course. Is it possible that the speed causes some form of gravitational effect that causes nearby atoms to be impacted in some way? These are the kind of questions I'm trying to answer. Knowing that something happens is nowhere near as much fun as knowing why. I realize many of you are wondering why I'm asking such silly questions, for me it's just a quest for understanding. The two planes and the two nuclear clocks would be a good model for me as they are based on slower speeds and exist on the earth.

It all boils down to the fact that light has a constant speed for everyone. This is a natural property of light just as much as inertia is a natural property of matter.

Because of this, observers with relative motion with respect to each other will measure the interval between the same two events differently. They simply have different ideas about how much time took place between them.

If you have two spaceships A an B, passing each other at a relative speed of 0.866c. Ship A will measure that ship B's clock ticks half as fast, but Ship B will measure that it is Ship A's clock that runs half as fast. According to some observer with a relative velocity of .999c to ship A, Ship A's clock runs almost 1/71 as fast as his and ship B's clock runs almost 1/264 as fast.(1/3.718 time as fast as Ship A's clock.)

To some observer, you right now are moving so close to the speed of light, that just your moving your hand will cause it to age considerably faster or slower than the rest of your body. You of course, notice no such aging difference.

The type of physical mechanism you are looking for just can't be made to account for these types of differences between observers in different frames.

Originally Posted by (In)Sanity

I know they did the whole test with the two nuclear clocks and the planes and ended up with them off by one second or something. I just question why is this and not that it just is.

.... Knowing that something happens is nowhere near as much fun as knowing why. I realize many of you are wondering why I'm asking such silly questions, for me it's just a quest for understanding. The two planes and the two nuclear clocks would be a good model for me as they are based on slower speeds and exist on the earth.

Science does not even attempt to explain why things work. It only explains how they work.

"How" is science.

"Why" is theology.

Time dilation has nothing whatever to do with the inner workings of any specific physical mechanism. It applies to spring-powered clocks, pendulum clocks, atomic clocks. the aging of biological systems, the decay of nuclear materials (which is random at the level of individual nucleii). It involves the behavior of time itself. We don't know what "time" is. It has no weight, it does not emit photons, it has no odor, ..... But whatever it is, it is what is measured by clocks, and whatever it is that clocks measure, it is dependent on the specific reference frame. Moreover, whatever it is, it has a meaning locally but not over distance, whatever distance is.

If you want to understand how time works, read any good book on special relativity. Einstein's discussions are quite good.

If you want to understand why time works that way, consut a priest, a shaman, a Rabii, or a witch doctor.

We don't know what "time" is. It has no weight, it does not emit photons, it has no odor, ..... But whatever it is, it is what is measured by clocks, and whatever it is that clocks measure, it is dependent on the specific reference frame.

Well this explains everything. It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change. We may not know why all matter or energy behaves the way it does or cycles in the fashion it does but we certainly can say time is just our counting and quantifying of these changes. We also known that we can influence these cycles in a predictable way. Every single thing you can think of that you can associate with time is directly related to some change in matter and/or energy. Even your very thoughts about how to answer this took time and changes in matter and energy. The ticking of your wind up clock is not caused by time, it's caused by mechanical force and friction.

Come back down to the simple level for a moment and work your way back up. You'll find that only the physical universe exists and that time is our creation and nothing more.

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Kind of what I was getting at.

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Neither you nor anyone else knows any such thing.

Originally Posted by DrRocket

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Neither you nor anyone else knows any such thing.

Is there any reason to suspect that time is anything other than a measurement of relative motion? If so, what are the reasons for this, and if not, why do people even wonder about it?

Originally Posted by KALSTER

Originally Posted by DrRocket

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Neither you nor anyone else knows any such thing.

Is there any reason to suspect that time is anything other than a measurement of relative motion? If so, what are the reasons for this, and if not, why do people even wonder about it?

I honestly think "time" has been distorted in meaning so badly over the years that people start to have misconceptions about it.

It's statement like this "In relativistic contexts, however, time cannot be separated from the three dimensions of space, because the rate at which time passes depends on an object's velocity relative to the speed of light and also on the strength of intense gravitational fields, which can slow the passage of time."

http://en.wikipedia.org/wiki/Spacetime

It's these kind of statements that make people confused.

In reality speed and gravity appear to slow the molecular structure to cause the measurements we obtain to be slow in relation to our normal time frame. Statement like the above make it appear that time is something in and of it's own. That however is not the case. If you stop all matter you have effectively stopped all time.

Take for example a nuclear clock.

http://en.wikipedia.org/wiki/Nuclear_clock

"Atomic clocks do not use radioactivity, but rather the precise microwave signal that electrons in atoms emit when they change energy levels."

What would cause a nuclear clock to begin to read slow in comparison to other clocks around it ? Short of electric failure the only thing I can think of is if that the oscillations emitted by atoms would have to change in frequency relative to other clocks. One would say that speed or gravity would cause this to happen, the big question still remains on the table as to why? To say time has slowed translates directly in to changes in matter and or energy. So what is it about speed that causes molecules to slow, I assume it has to be gravity. The grater speed producing more of it causing the atomic structure to slow.

I realize I'll never convince some people of this as they have in their head that time is some fantastic unknown force at work in the universe. To them I put out the challenge to tell me what effects would your so called time slowing have on the nuclear clock mentioned above to cause it to run slower. In the end it directly translates in to slowing of matter and energy in a directly proportional way. So lets call an apple an apple.

Originally Posted by (In)Sanity

What would cause a nuclear clock to begin to read slow in comparison to other clocks around it ? Short of electric failure the only thing I can think of is if that the oscillations emitted by atoms would have to change in frequency relative to other clocks. One would say that speed or gravity would cause this to happen, the big question still remains on the table as to why? To say time has slowed translates directly in to changes in matter and or energy. So what is it about speed that causes molecules to slow, I assume it has to be gravity. The grater speed producing more of it causing the atomic structure to slow.

But that explanation fails For multiple reasons. If you actaully compare two clocks in a gravity field, their times will not vary according to the difference in the local strength of the gravity field. Sronger local gravity does not always mean a slower clock.
Examples include clocks on the surface of Earth and Uranus, or a clock sitting in a hollow at the center of the Earth vs a clock stiing on the surface of the Earth. The surface gravity on Uranus is slightly less than that of Earth's, yet the Clock on Uranus runs slower. The Clock sitting in the hollow at the center of the Earth will experince no gravity (Newton's Shell theorem), yet will run slower than a closk on the Surface. Yet a clock removed to deep outer space and feeeling little or no gravity will run faster than the the other two.

Nor can it explain te following scenario:

Two indentically constructed clocks are separated by a distance and are accelerating along the line of their separation. They maintain the same distance from each other as they do so (as seen by an outside observer), so they always travel at the same speed. and experience the same acceleration. In other words, they experience exactly the same physical conditions. Yet the clock that is "in front" Will run slower than the clock "behind" it.

The differnce in the rates of these clocks can not be explained by any mechanistic physical cause acting on one or the other, because there is no such difference in the physical conditions under which each clock operates.

There is more to the comparison of different clock rates than: "Something makes clock 1 run slow, so in comparison, it thinks clock 2 runs fast".

This is something I've been thinking about for years. I've come to the conclusion that if Einstein was right then Time is variable (apparently only progressively) because of the statement that you take two infants, put one on a shuttle and send it nigh unto the speed of light and bring it back again, the two infants are different ages. The one on the shuttle might still be a small child while the other is a grown man. Now this is something that I have heard for a long time, is my understanding of Einstein's theory wrong? If not then this example shows that the amount of time experienced was different depending on speed.

Originally Posted by DrRocket

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Neither you nor anyone else knows any such thing.

"One finds that time just disappears form the Wheeler-DeWitt equation, it is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time - that the fundamental description of the universe must be timeless.

We never really see time, we see only clocks. If you say this object moves, what you really mean is that this object is here when the hand of your clock is here, and so on.

The problem, in brief, is that time may not exist at the most fundamental level of physical reality" ~~Carlo Rovelli

"Our clocks do not measure time. Time is defined to be what our clocks measure, therefore time is defined by the number of clicks on our clocks." ~~ NIST

Two indentically constructed clocks are separated by a distance and are accelerating along the line of their separation. They maintain the same distance from each other as they do so (as seen by an outside observer), so they always travel at the same speed. and experience the same acceleration. In other words, they experience exactly the same physical conditions. Yet the clock that is "in front" Will run slower than the clock "behind" it.

If they traveled the same distance and at the same speeds and the only difference between them is how far apart they are spaced then this would not fit in to any theory at all. There is no difference in speed, acceleration or distance traveled. You simply have some poorly crafted clocks. If you said one was moving a little faster then the other then I could see why this might happen. Unless of course outside gravitational fields are interacting with the clocks under acceleration (not at rest) to introduce variables not scene by the observers. For example the concentration of sub atomic particles in it's flight path.

Perhaps it's gravitational force during acceleration that causes the molecules to slow. There has to be a physical reason why this is happening even if it's not something we yet understand. I'm not at all convinced in the slightest that it's "time". Unless of course you are using it as a measurement to determine how long acceleration has taken place, etc. Perhaps we have lumped many concepts that are understood and not understood under the one term "time".

So has anyone compared how clocks drift under constant acceleration vs constant high speed ? Forget Einstein for a while and look at real world proof vs formulation. I'm not saying he's right or wrong, I just would like to analyze the results of actual experiments conducted. I suspect once we understand how gravity really works we'll understand why this is happening. It's kind of hard to explain these thing when we can't even explain why we stick to the planet.

Originally Posted by (Q)

Originally Posted by DrRocket

Originally Posted by (Q)

Originally Posted by (In)Sanity

It would appear you feel time is something more then changes in matter and or energy. Think about how every single device we have to measure "time" works and you will see that time is nothing more then a mechanical man made way to keep track of change.

At below the Planck level, time doesn't really exist as we assume we know it, hence we are most likely not measuring "time" itself but are really only measuring the clocks we construct.

Neither you nor anyone else knows any such thing.

"One finds that time just disappears form the Wheeler-DeWitt equation, it is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time - that the fundamental description of the universe must be timeless.

We never really see time, we see only clocks. If you say this object moves, what you really mean is that this object is here when the hand of your clock is here, and so on.

The problem, in brief, is that time may not exist at the most fundamental level of physical reality" ~~Carlo Rovelli

"Our clocks do not measure time. Time is defined to be what our clocks measure, therefore time is defined by the number of clicks on our clocks." ~~ NIST

1) To the extent that this makes any sense, you are talking about quantum gravity, and there is NO current viable theory of quantum gravity. The Wheeler-DeWitt equation is speculative and not well-defined in general.

2) General relativity already tells you that there is no global notion of time. That does not require quantum gravity.

Nobody has any fundamental definition for "time". Einstein was of the opinion that it is probably statistical in nature, but did not provide any rigorous definition of what that means.

You are left with simply that "time is what clocks measure".

Originally Posted by (In)Sanity

Yet the clock that is "in front" Will run slower than the clock "behind" it.

If they traveled the same distance and at the same speeds and the only difference between them is how far apart they are spaced then this would not fit in to any theory at all. There is no difference in speed, acceleration or distance traveled. You simply have some poorly crafted clocks. If you said one was moving a little faster then the other then I could see why this might happen. Unless of course outside gravitational fields are interacting with the clocks under acceleration (not at rest) to introduce variables not scene by the observers. For example the concentration of sub atomic particles in it's flight path.

[/quote]It is exactly what Relativity predicts will happen; It is a consequence of the Relativity of Simultaneity.

Perhaps it's gravitational force during acceleration that causes the molecules to slow. There has to be a physical reason why this is happening even if it's not something we yet understand. I'm not at all convinced in the slightest that it's "time". Unless of course you are using it as a measurement to determine how long acceleration has taken place, etc. Perhaps we have lumped many concepts that are understood and not understood under the one term "time".

So has anyone compared how clocks drift under constant acceleration vs constant high speed ? Forget Einstein for a while and look at real world proof vs formulation. I'm not saying he's right or wrong, I just would like to analyze the results of actual experiments conducted. I suspect once we understand how gravity really works we'll understand why this is happening. It's kind of hard to explain these thing when we can't even explain why we stick to the planet.

There is the "Clock Postulate" that states that acceleration has no effect on clocks.

It has been tested by placing radioactive isotopes in high speed centrifuges. By varying the radius at which the sample travels, you can have any combination of speed and acceleration. You can test different accelerations with the same speed, or different speeds with the same acceleration. The result was that the value of the acceleration has no effect.